Aeronautical propeller spinner



March 15, 1960 T. E, DOHERTY ETAL 2,928,475

AERONAUTICAL PROPELLER SPINNER V 2 sheets-sheet 1 Filed Oct. 28, 1954 INVENTORS I BY//f ATTORNEY March 15, 1960 T. E. DOHERTY EVAL 2,928,475

AERONAUTICAL PROPELLER'SPINNER 2 Sheets-Sheet 2 Filed Oct. 28, 1954 rf/oM/Ls' E, @offri/ery my Poseer .9. /f-L L w ,United States Y Patft F 2,928,415 VAERoNAU'rICaL PaoPELLER SPINNER Thomas E. Doherty, Glastonbury, and Robert B. Keller,

Simsbury, Conn., assigner-s to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Applica-tion October 28, 1954, Serial No. 465,416 s claims. (ci. 17o- 135.743)

This invention relates to an aeronautical propellery almost continuouslyY in order to maintain a substantially constant propeller speed in different Hight attitudes 'and in ydifferent altitudes of'ilight. This will cause the pitch change mechanism to become heated and, assum-l 4ing an hydraulically controlled propeller, the hydraulic tluid will also become heated. While in most installations the normal flow of air over an'daround the propeller hub assembly is suiicient for propeller cooling purposes, in the exemplary installation there may be ns'uflicient air-ow for cooling purposes. That is, the propeller may befmounted on a large radial engine and there is the possibility that by reason of the large radial Vdimensions of the engine, a region of elevated ambient a'ir pressure -may be created in flight forwardly ofthe radial engine and there will be insutlicient air ow in the propeller hub region to properly cool the propeller. t

It is the general object of the invention to provide an aeronautical propeller spinner which will induce air ow in intimate contact wtih that portion of the propeller assembly which may require cooling.

Other more specific objects as well as advantages of the invention will become apparent to those skilled in the art from the following description of the annexed drawings which, by way of example only, illustrate two specific embodiments of the invention and in which,

' Fig` l is a vertical longitudinal cross-sectional view ot a spinner constructed in accordance with the invention;f

Fig. 2 is a view similar to Fig. 1 but showing an-alternative in construction; and

Fig. 3 is a detail cross-sectional view taken as indicated by the vline 3-3 of Fig. 2. .v

4For convenience in describing a spinner 10 which is constructed in accordance' withv the present invention, the said spinner is shown as associated with a four-blade propeller assembly comprising a hub or barrel H providing the principal supportv for the propeller blades which may be securedthereto in the locations designated at B, B. The particular propeller assembly shown also includes a `dome D projecting forwardly of the hub or barrel H and which contains at least part of the propeller pitch changing mechanism and the hydraulicuid vfor'actuatirig the same. Thus, in the exemplary installation, itis most desirable toV providev coolingffor the domeD so as to reduce the temperature of the propeller '.controlsfluid` and the pitch changing mechanism.

The spinner 10 which-is particularly adapted for cooling purposes comprises a generally frusto-conically shaped shell which is made up of two sections, a front or nose section 12 which surrounds the dome D and a rear Isection 14 which surrounds the propeller hub H. The saidfront and rear sections 12 and 14 are joined in end-to-end relationship on a connecting ring 16, being secured thereto as by rivets 18, 18 or the like. The connecting ring 16 is generally L-shaped in cross section, having a radially inwardly projecting annular wall 20. A support ring 22, also of generally L-shaped crosssectional configuration, is secured as by rivets 24, 24 to the inwardly projecting wall 20 so that one wall 26 of the support ring 22 projects longitudinally rearwardly of the spinner shell. A half-round soft rubber or rubberlike sealing and support strip 28 is cemented or otherwise secured to the inner surface of the longitudinally rearwardly projecting ring wall 26. This sealing 'strip embraces a longitudinally forwardly projecting Wall 30 of a third L-shaped ring 32 which is secured as by bolts 34, 34 on the front face of the propeller hub section H.

The rear section 14 of the spinner shell has a plurality of blade openings 36, 36 through which the propeller blades project and-detachable panels 38, 38 are provided in the spinner section 14 so that the shell can be placed on the propeller assembly from the front there- That is, the panels 38, 38 are removed from the section 14 and then the shell is thrust rearwardly over the propeller hub H so that the propeller blades are received `within the vopenings 36, 36. Then the panels 38, 38 are replaced in the section 14. It willY be seen that in the aforedescribed spinner shell, `the innerring 32 is not detachable with the shell. The said ring 32 is 'secured on the hub and the shell is placed therearound provided in more or less than the two sections shown and can be arranged for mounting on the propeller assembly in various other ways. In most cases, it will be desirable to provide additional spinner support means secured to the propeller assembly preferably rearwardly of the propeller blades. However, since a variety of additional support arrangements can be made in accordance with conventional practice, no specific arrangement is shown.

vIt is important to observe that the three-ring support arrangement, comprising the rings 16, 22 and 32, provides an imperforate annular bulk-head within the spinner 10 forwardly of the propeller hub H. The said annular Vbulkhead prevents the flow of air rearwardly thereof.

It is also important to observe that the front of the .nose section 12 of the spinner shell is provided with a large central opening 40 for the ilow of ram air in accordance with the present invention. Air passing through the opening40 will ilow around the dome D, as shown f generally by the arrows, toward the three-ring annular bulkhead. While the nose section 12 'does not snugly embrace the dome D, it is spaced relatively close to Vthe front end portion of the said dome so that the annular passage defined therearound will constrain the air flo'w -and force it into intimate association with the' dome D. A generally cylindrical bale or shroud 52 is secured within the nose section 12 as by rivets 44, 44 on a support ring 46 to surround the intermediate and rearward portion of the dome D in spaced relationship. As .will beV air, andthusa velocityhead'decrease and a,l static headV e increase, it is provided to constrain the air flow in intimate contact with thefdome D for effective cooling thereoflith? Shroud ,were vnot Provided, turbuleneimight be indutedinV the expanding airaround the dome and cause inefficient propeller dome cooling. Y N

,t 1a-forse that 110W will beacowmmadatd thwughthe spinner 10, the nose section 1`2of the'fspinner is provided with a pluralityof circumferentially spaced-segmental openings 4,8,` 48 'which preferablyvequal in number the propeller blades of the installation and which are preferably locatedrsoA that Vone such opening 48' will be'=dis'-, posed between adjacent t propeller blades; segmental openings 48,7748 is partially closedrby `a seg; mental louvcr-,lilte panel50 which'ris secured, as by rivets 'fegeasgara Y f Y related to the size or dimension oflthe Vnose opening 40.

More specifically, the shroud is provided in a predeter- A Vmined sizeV according totllesize of the nose opening so as tocontrol expansion'of the ram air for efficient cooling and to provide for internal pressure greater than external pressure at the discharge openings. The size or nach or the SALSA-externally of the` shell adjacent'fthe front 'edgef` y of theY opening; 'l'he louverlil e panels,50, V50, are provided to preventturbulence in the air stream discharged Y i throughthe openings 48, 48 and to direct the air in `a smooth stream 'rearwardly of the spinner shell. Y

It will be apparent to-those skilled in the art that in Hight, the air pressure on the,Av outside surface of the spinner shell adjaceilt'the `louvered openings 48, 48 willbe considerably reduced by the jet pump or"scupper" effeot. of the panels 50, 50 and will be less than the external surface pressure adjacent the `nose openingI 40.

ln' order "to have discharge `flow through the openings Y 4S, 4 8, the'internal pressure adjacent the said openings `rnustbe greater than the external pressure. fIt is a' feature `of'atnspinner constructed in accordance with this invention that ram air in passingfrorn the-nose openingjit) tothe dischargeV openings 48, 48 is not permitted to suffer pressure losses C`4within' the spinner to Vthe ,point where internal pressnre'is'equalto or less thanexternal priessuelatV the said,A c iischarge openings, That is, V'the cylin-` area of the nose ,opening 40 and the total area of the 1 discharge openings 48,48 'andthe speed fthe aircraft control the volume of ram air flow through thesrpinner Y per unit of time. Accordingly, if-an aircraft is expected to spend most of-its `flight time=a`t`or nearone speed, whichimay be'the cruising speed, the nose and discharge openingsA are selectedV to accommodate ram air ow in suicintvolume to"'take care of the anticipated propeller cooling requirements Vat'saidone speed. Itrshouldvbe understood, however, Jthat a relatively largerange ofV `selection is permitted.

, 'It -should `also bep-understood that Athe fore Vand/or: aft 4location ofthe dischargegopenings 48, '48' is notcritical,V

and depends only uponexternal pressure conditions. That is, the said openings may be'located forwardlyof thepropeller-hubas shown, in the propeller hub region,

-orrearwardly-thereof. lf located adjacent or rearwardly o f-,tliehubghe ram` air stream may providevadditional pro-` peller;qcoolinglinpassing; over, the hub. -However, external Y .pressure-conditions may notpermit locating the discharge Y openings-rearwardlyofrthepositionshown. For example, aflargefadial engine?may` create a region of Vhigh ambient 1pr essure .for;wardly 4of itsface. Under such conditions itmay-be impossible;to.1discharge the VVram-air through discharge,` cpr'eningsV located .adjacent or4 rearwardlyof the' propellerhub. ltrany locationfofthefdischargeopeninga `4,8, 48-the air ightbulkhead, such` as provided-bythe annular-yringaeahould be4 located adjacent to andreardricafshroud 42`is constructed and arranged-,to permit I sufficient A expansion ofv the ramair to increaseV its static pressure asArequired Vfor eicient discharge while at the same time the ram air is constrainedzto,'flowinintimatel contact'with the dome Dforetlicientfcooling thereof'.

Considering airow and pressures in thespinnervn greaterdfetaihit will be observed that the.,airundergoefs apressurenncreaseldue Jto-irnpact as itentersfthe spinner i f `nose opening 40."l 'Immediately upon entering, the `said opening o the, air isv permitted, to expand' as it Vpasses 'over the `forward portion4 ofthe dome D, it being-observed thatthe annular passageway throughwhich thefair passes afdcimL-Sidfofwafd dQmSPOYQU nfeses inlvolmlle rearwardly by virtue of a rapid increase in its mean diaxneter. During such expansion of the air, its velocity pres-v surer or 'headldecreases and itsl static pressure or head Vint'freasfeso 'The forwardportion ofthe shroud 42 adjaentnzt'he `rivets Y114, 44 permits the expansion ,foco'ntinug wardly of; the Vsaid openingeto further constrain and-direct Allovv rof;- the 11amairyand to Yprevent-un'desirabld pressurereduci-ng expansiongthereof'., l

hutthe. remaining portionlthereof provides an 4Vannular i pair passageway of substantially constant mean diameter `andsubstantielly constant cross-sectional area. Thus,=^expansion of the air-ceases when itpasses adjacent said ,remaining shroud portion and the {velocity and stati'e'pres- A suresolr the -air remain substantiallyacoustant until it reachesihe trailingtedge of saidshroud where,prior to y l v-discharge, it again expands with an accompanying Qvelocity,;pressuregdecrease and static pre,ssurejinc-zrease.` By-so In Fig; 2 there, is shown` a -spinner'whichfisz identical lto, the previously described spinner. Theonly modificationofthe previously described construction' is-provided thy.; the); addition; of lan" annular heatjexchanger` indicated Vgenerally'tby the reference nurmeral 51,. Y The heatA ext `changer-51,has-5a hublwhich embraces the dome. D and Almayjfbefcionsideredfa,part thereof. VTh at` is,tthe hub 5.3

has atpluralityi of spiralY grooves 54,1 54 onits innergsurfacewhieh circulate-the propellenuidthereim-- -Such Scir- "oulationfv oftle'propeller uidis provided onlywfor :the fpiirpose,v off'co'oling. ,-To further-,f facilitat'e,the-cooling of the propeller iluid, theheatv exchanger \51lias -,a plurality of Vradilallyffoutwardly, projecting; extended surfaces or tins 56';` 5,6 whichfextend do `the; shroudf42; Thus; ,when

'rain air passes,` through v.the annular opening, defined AbetweenY the vshroud 421 and the dome D; it fwill -pass along the cooling fins; 56, .5610; more 5 efficiently cooly the. pro- :peller fitluid contained :within'the"grooves` 54, 54. fAc- -cordingly, propeller `cooling `may, be--enhanced iby; incorporating the heat exchanger 51 in the construction.`

t While we-:have :describedtthe: invention in Aconnection I with twospe'cicforrns, itshould bezunderstoodthat Welelairn asloriinvention:

-limitingxjr Vcontrolling expansion of the air, the vahr-outil Y 42.aminimizes turbulenceiarund the dorneandiprovidesfor asmoothair -flow thereover whereby toprovidetfor eicient `cooling' ofthe same.. The shroud `4,2- is iso Voon- "st'ructedland arranged, howeverfthat it does not unduly rlirnitairexpnsion with the resultthatstatic pressure will .be inadequate for efficient discharge at Athe, openings 48,i48. Stated differently, the shroud 42controls expansi6n`-ofth`eair so as to provide for eilicient coolingaand at'tlie same timeproyides for' internal"pressurekgreater` .'thaneitternl pressure'at the disehargeopenings; l

in any-:specific `installation depends' upon andffis directly of fthe'ftypet-.ha'vng aiectir'g blades, "fthe l combination fcomprisiugzifa generally Vtruste-c,on'icallyl shaped 'shell :surrounding the, hub -in1 Aspacedrelationship with itsrgsmalle; :diameter endiptoeotf "saidehelliihavinglf nose openingitolreceive'fram l g also having atlea one )radial .openingfspaeed rearwardly of tlrenose'to dischargeftlie `ramflair stream, a-:luverfjflke --nventionfis; notiito 'be llirnitedf to' thevLdescribed'forml Votherwise: lthan indicated bytle ciaims *which',vfollyvr.;4 y;

nner-retornan;aeronauticlipropeller hub :and a: plurality Sofiadially pjr iid of 'but -adjacent't'o the discharge opening :to block rearward ow of the air stream -in the spinner shell and to direct the air stream into the discharge opening, and a cylindrical shroud secured internally of the shell and extending substantially longitudinally thereof between the nose and discharge openings to direct air ow toward the central portion of the hub and to control expansion of the air stream for efficient cooling of thehuband at the same time to provide for an internal ,pressure greater than external pressure at said discharge opening.

2. In a cooling spinner lfor an aeronautical propeller of the `type having a hub and a plurality of radially projecting blades, the combination comprising a generally frusto-conically shaped shell surrounding the hub in spaced relationship with its smaller diameter end projecting forwardly therefrom to provide the spinner nose, said shell having a nose' opening to receive ram air and also having a plurality of circumferentially spaced radial openings located rearwardly of the nose to discharge the ram air'stream, a louver-like panel for each of said discharge openings secured to the shell forwardly of its respective opening to direct air discharged therethrough rearwardly of the spinner, an imperforate annular bulkhead extending between the spinner shell and the propeller hub rearwardly of but adjacent to the discharge openings to block rearward llow of the air stream in the spinner and to direct the air stream into the discharge openings, and a cylindrical shroud secured internally of the shell and extending substantially longitudinally thereof between the nose and discharge openings to direct the ram air stream toward the central portion of the hub and to control expansion of the air stream for eicient cooling of the hub and at the same time to provide for an internal pressure greater than the external pressure at said 'discharge openings.

3. In a cooling spinner for an aeronautical propeller of the type having a hub, a plurality of radially projecting blades and a dome projecting forwardly of the hub and containing propeller pitch changing mechanism and hydraulic iluid therefor, the combination comprising a generally frusto-conically shaped shell surrounding the hub in spaced relationship with its smaller diameter end projecting forwardly and surrounding the dome to provide the spinner nose, said shell having a nose opening to receive ram air and also having at least one radial opening spaced rearwardly fromk the nose to discharge `the ram air stream, an irnperforate annular bulkhead extending between the propeller hub and the shell rearwardly of but adjacent to the discharge opening, and a cylindrical, shroud secured internally of the shell and surrounding the dome in spaced relationship and in communication with the said nose opening to direct the ram air stream over the dome and to control expansion of the air stream for eticient cooling of the dome and at the same time to provide for an internal pressure greater than external pressure at said discharge opening.

,4. In a cooling spinner for an aeronautical propeller of'lthe type having a hub, a plurality of radially projecting blades, and a dome projecting forwardly of the hub and containing propeller control fluid, the combination comprising a generally frusto-conically shaped shell surrounding the hub in spaced relationship with its smaller diam. eter end projecting forwardly and surrounding the dome to provide the spinner nose, said shell having a nose' opening to receive ram air and also having a plurality of circumferentially spaced radial openings located rearwardly of the nose .to discharge the ram air stream, an imperforate annular bulkhead extending between the spinner shell and the propeller hub rearwardly of `but adjacent to the discharge openings to block rearward ow of the air stream in the spinner and to direct the air stream into the discharge openings, and a cylindrical shroud secured internally of the shell and surrounding the dome in spaced relationship and in communication with the nose opening to direct the ram air stream around the dome and to control expansion ofthe air stream for eilcientcooling of the dome and at the same time topriwide for an ing blades, and a dome projecting forwardly of the hub and containing propeller control uid, the combination comprising a generally frusto-conically shaped shell 'vsurrounding the hub in spaced relationship with its smaller diameter end projecting forwardly and surrounding the dome to provide the spinner nose, said shell having a nose opening to receive ram air and also having a plurality of circumferentially spaced radial openings located rearwardly of the nose and forwardly of the propeller hub to discharge the ram air stream, an imperforate annular. bulkhead extending between thespinnershelland the forward end of the propeller hub to block rearwardllow, of the air stream in the spinner and to direct the air stream into the discharge openings, and a cylindrical shroud secured internally of the shell and surrounding the dome in spaced relationship and in communication with the nose opening to direct the ram air stream around the dome and to control expansion of the air stream for eiiicient cooling of the dome and at the same time to .provide for an internal air pressure greater than external pressure at said dischargeopenings.

6. In a cooling spinner for an aeronautical propeller of the type having a hub, a plurality of radially projecting blades, and a dome projecting forwardly of the hub and containing propeller control iluid, the combination comprising a generally frusto-conically shaped shell surrounding the hub in spaced relationship withI its smaller diameter end projecting forwardly and surrounding the dome to provide the spinner nose, said shell having a nose opening forwardly of the dome and also having a plurality of circumferentially spaced radial openings lo cated adjacent the rear end of the dome and forwardly of `the propeller hub to discharge the ram air stream, a louver-like panel for each of the said discharge openings secured to the shell forwardly of its respective opening to direct air discharged therethrough rearwardly of the spinner, an imperforate annular bulkhead extending from the front end of the'propeller hub to the spinner shell Vto block rearward flow of the air stream and to direct .the air stream intov the discharge openings, and a cylindrical shroud secured internally of the shell and surrounding the dome in spaced relationship and in communication with the nose opening to direct the ram air stream over the dome and to control expansion of ,the airA stream for eflicient cooling of the dome and at the same time to provide for an internal pressure greater than external pressure at said discharge openings.

7. Means for cooling an aeronautical propeller of the type having a hub, a plurality of radially projecting blades, and a dome projecting forwardly ofthe hub and containing propeller control fluid, said means comprising in combination, a generally frusto-conicallyshaped spinner shell surrounding the hub in spaced relationship with its smaller diameter end projecting forwardly therefrom and surrounding the dome to provide the spinner nose, said shell having a nose opening forwardly of the dome and also having a plurality of circumferentially spaced i radial openings spaced rearwardly of the nose to discharge endisun'bundug the domein-spcedfrelationship; to pro` vide the v*.spirmer inose, `Sfaid'shellihzrwing' a'nose opening DnwrdlY `of the domyelt'ore'eciv ramair and also having a plurality'of ':ire'u'-rnferenti'ally r spaced radial openings rearwadlyf of'the-noselto discharge the ram air stream;l

andL theshell rerwardlyfoffbut adjacentto the dischargeV 15:`

openings to'blbckrearward flow 'of/the air stream in the Y "spinner isliell'an'df iuokiir'ett the airfstream` into 'tl1e"dis=' Y char-ge -openings, aj Vcylindrical vshroud fsecured internally of theshellandsurroundingthe dome in spacedrelafcioixngesayrisl t6 direct lt'heframir Stream' around-'ith'efdbm nd adiacenti-thereto i A A RefeencesjCted-fint ihele of this 'patent UNITED'STATES'TATENTS 

